Research Centre for Plant RNA Signaling and Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 311121, China.
Division of Biostatistics and Bioinformatics, University of California, San Diego, California 92093.
Plant Physiol. 2020 Aug;183(4):1883-1897. doi: 10.1104/pp.20.00499. Epub 2020 Jun 5.
Vivipary, wherein seeds germinate prior to dispersal while still associated with the maternal plant, is an adaptation to extreme environments. It is normally inhibited by the establishment of dormancy. The genetic framework of vivipary has been well studied; however, the role of epigenetics in vivipary remains unknown. Here, we report that silencing of () promoted precocious seed germination and seedling growth within the tomato () epimutant - () fruits. This was associated with decreases in abscisic acid concentration and levels of mRNA encoding 9-cis-epoxycarotenoid-dioxygenase (SlNCED), which is involved in abscisic acid biosynthesis. Differentially methylated regions were identified in promoters of differentially expressed genes, including knockdown also induced viviparous seedling growth in fruits. Strikingly, ripening reversion suppressed vivipary. Moreover, neither /-virus-induced gene silencing nor transgenic -RNA interference produced vivipary in wild-type tomatoes; the latter affected leaf architecture, arrested flowering, and repressed seed development. Thus, a dual pathway in ripening and -mediated epigenetics coordinates the blockage of seed vivipary.
胎生，即种子在与母体植物仍有联系的情况下在散布之前发芽，是对极端环境的一种适应。它通常受到休眠的建立的抑制。胎生的遗传框架已经得到了很好的研究；然而，表观遗传学在胎生中的作用尚不清楚。在这里，我们报告说，沉默 () 促进了番茄 () 突变体 - () 果实中早熟种子的发芽和幼苗的生长。这与脱落酸浓度的降低和编码 9-顺式-环氧类胡萝卜素双加氧酶 (SlNCED) 的 mRNA 水平降低有关，SlNCED 参与脱落酸的生物合成。在差异表达基因的启动子中鉴定到差异甲基化区域，包括 敲低也诱导了 果实中的胎生苗生长。引人注目的是，成熟逆转抑制了胎生。此外，/ - 病毒诱导的基因沉默或转基因 -RNA 干扰都没有在野生型番茄中产生胎生；后者影响叶片结构，阻止开花，并抑制种子发育。因此，成熟和 - 介导的表观遗传学中的双途径协调了对种子胎生的阻断。
